Cholesterol crystal

A cholesterol crystal is a solid, crystalline form of cholesterol found in gallstones and atherosclerosis. Gallstones occurring in industrialized societies typically contain more than 70-90% cholesterol by weight, much of which is crystalline.^[1] Cholesterol crystals are a hallmark of atherosclerosis, which is believed to be an early cause of atherosclerotic inflammation.^[2] Cholesterol phase transition from liquid to crystalline form is linked to inflammation.^[3] Cholesterol crystals are believed to induce inflammation by activation of the NLRP3 inflammasome.^[4][5]

In addition to being a source of inflammation, cholesterol crystals are believed to cause mechanical injury by tearing tissue, causing plaque rupture.^[6] Impaired removal of cholesterol crystals from demyelinated nerves by macrophages is believed to be associated with multiple sclerosis, and this remyelination failure is particularly impaired in the elderly.^[7][8]